 /* crypto/bn/bn_sqr.c */

 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)

 * All rights reserved.

 *

 * This package is an SSL implementation written

 * by Eric Young (eay@cryptsoft.com).

 * The implementation was written so as to conform with Netscapes SSL.

 * 

 * This library is free for commercial and non-commercial use as CrLONG32 as

 * the following conditions are aheared to.  The following conditions

 * apply to all code found in this distribution, be it the RC4, RSA,

 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation

 * included with this distribution is covered by the same copyright terms

 * except that the holder is Tim Hudson (tjh@cryptsoft.com).

 * 

 * Copyright remains Eric Young's, and as such any Copyright notices in

 * the code are not to be removed.

 * If this package is used in a product, Eric Young should be given attribution

 * as the author of the parts of the library used.

 * This can be in the form of a textual message at program startup or

 * in documentation (online or textual) provided with the package.

 * 

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. All advertising materials mentioning features or use of this software

 *    must display the following acknowledgement:

 *    "This product includes cryptographic software written by

 *     Eric Young (eay@cryptsoft.com)"

 *    The word 'cryptographic' can be left out if the rouines from the library

 *    being used are not cryptographic related :-).

 * 4. If you include any Windows specific code (or a derivative thereof) from 

 *    the apps directory (application code) you must include an acknowledgement:

 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"

 * 

 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 * 

 * The licence and distribution terms for any publically available version or

 * derivative of this code cannot be changed.  i.e. this code cannot simply be

 * copied and put under another distribution licence

 * [including the GNU Public Licence.]

 */



#include "crypto/CrBNConfig.h"

#ifdef _BN_SQR_C



//#include <stdio.h>

#include "crypto/CrBN.h"

#include "crypto/CrBNLcl.h"







 /* r must not be a */

 /* I've just gone over this and it is now %20 faster on x86 - eay - 27 Jun 96 */

CrINT32 BN_sqr(BIGNUM *r, BIGNUM *a, BN_CTX *ctx)

	{

	CrINT32 i,j,max,al;

	BIGNUM *tmp;

	BN_ULONG *ap,*rp;



	tmp=ctx->bn[ctx->tos];



	al=a->top;

	if (al == 0)

		{

		r->top=0;

		return(1);

		}



	max=(al*2);

	if (bn_wexpand(r,1+max) == NULL) return(0);

	if (bn_wexpand(tmp,1+max) == NULL) return(0);



	r->neg=0;



	ap=a->d;

	rp=r->d;

	rp[0]=rp[max-1]=0;

	rp++;

	j=al;



	if (--j > 0)

		{

		ap++;

		rp[j]=bn_mul_words(rp,ap,j,ap[-1]);

		rp+=2;

		}



	for (i=2; i<al; i++)

		{

		j--;

		ap++;

		rp[j]=bn_mul_add_words(rp,ap,j,ap[-1]);

		rp+=2;

		}



	bn_add_words(r->d,r->d,r->d,max);



	 /* There will not be a carry */



	bn_sqr_words(tmp->d,a->d,al);



	bn_add_words(r->d,r->d,tmp->d,max);



	r->top=max;

	if (r->d[max-1] == 0) r->top--;

	return(1);

	}



#endif	//end of _BN_SQR_C



